简介：AbstractPurpose:To compare the stability of the posterior anatomic self-locking plate (PASP) with two types of popular reconstruction plate fixation, i.e. double reconstruction plate (DRP) and cross reconstruction plate (CRP), and to explore the influence of sitting and turning right/left on implants.Methods:PASP, DRP and CRP were assembled on a finite element model of both-column fractures of the left acetabulum. A load of 600 N and a torque of 8 N·m were loaded on the S1 vertebral body to detect the change of stress and displacement when sitting and turning right/left.Results:The peak stress and displacement of the three kinds of fixation methods under all loading conditions were CRP > DRP > PASP. The peak stress and displacement of PASP are 313.5 MPa and 1.15 mm respectively when turning right; and the minimal was 234.0 Mpa and 0.619 mm when turning left.Conclusion:PASP can provide higher stability than DRP and CRP for both-column acetabular fractures. The rational movement after posterior DRP and PASP fixation for acetabular fracture is to turn to the ipsilateral side, which can avoid implant failure.